I would have been perfectly happy had this series finished with City of Glass, the third book. Make it a trilogy. It seemed all wrapped up to me.
But no. Seems like Clare is going to milk this for all it's worth. This book was completely unnecessary to the series. And all I got from this was how terrible the romances are! The Shadowhunter and other beings plotlines are interesting, but her romantic storylines have ruined it. They are boring and frankly, a little stupid. Jace's actions frustrated me. He's an idiot and Clary just lets him get away with it. The boy needs a good slap to the face.